Fort Worth daily gazette. (Fort Worth, Tex.) 1882-1891, 1887-05-01
POPULAR SCIENCE.
Bits OF Information In Condensed Shape
That May Prove Usrful.

| formed an interesting experiment in
solidifyiDg carbonic acid gas at the Uni
versity of Wooster. Carbon dioxide was
generated in a cylinder of Bessemer steel
under pressure of 5000 pounds to the
| square inch. From there it was allowed
| to escape into condenser in the COndi-
! ton of solIditied gas, resembling snow
| flakes in appearance. The temperature
of this solidified gas is 1853 Fahrenheit
/ below zero. A small quantity of this gas
/ was then gathered and passed into 8
/ so-called "snow-ball," on one side of
which was a small depression. The
! ball was placed in q red hot crucible upon
which the intense heat of Bunsen burn
er was playing. A little mercury and
ether were dropped into the depression
on the "gas ball" and, Notwithstanding
! the intense hest, the mercury was imme-
distely frozen. Professor Bennett then
advanced one step higher Oy setting the
ether on FIRE, but still he was enabled to
pick out the frozen bulb of mercury. An
instance of this iast step, in which mer-
curry was frozen in a flame as well as over
red hot crucible, has never been record
ed in science, and was perfectly original
with Professor Bennett.
The Boston Herald thus describes an
electric mail 0OX which the Boston post
office authorities think of adopting:
letter is left by 3 carrier in 9 street box
of business concern. As the letter
drops into the box it completes an cleo
trio circuit, and a little bell contained in
clock hanging in the inner Office Of the
firm rings, thus announcing the presence
of the letter in the outer box. At the
same time that the bell notifies the ear
of the arrival of the letter in the box
without, q little white disk
falls across an opening in the
case of the clock, thus con-
veying the intelligence to TIE eye. A
common electric battery IS used, an
ordinary eight-day clock. employed, and
the whole continuance is very simple. 1t
will Immediately notify the occupant of
an office several stories above the street,
or the occupant CT lofty lat in an apart
ment hotel, or the busy housewife, # the
arrival of the letter, and will save the
carrier many needless steps and the
yexatious delays OcCasiOned by people
who will not answer the door bell.
As 8 finish or covering for walls and
ceilings, puIverized steatite is coming
into use quite satisfactorily. 1t is simply
sOapstOne. 1t takes 8 high polish, IS
pearl gray in tint, IS said to present the
best possible surface for painting, either
in Gil or water color, and, what is verV
desirable, will neither crack pOr chip. 1t
Is claimed for it that it is q non conductor
and non-absOrbent; that it can be washed
without injury; nails can be driven into
it without damage. When subject 20 heat,
moisture and chemical fumes it gives no
smell, and it does not turn yellow with
age. II is thought to be specially adapted
for hospitals, factories, cellars, mar
kets, etc.
+ novel application of electricity is
shown in pharmacy at Berlin. To pre-
+ vent mistakes In dispensing medicines
each bottle which contains highly dele
teriOus or poisonous drugs is made by its
own weight to hold open a circuit closer
connected with q battery and vibrating
. bell. The weight of the bottle being re-
r moved the push button beneath it rises by
the force of 6 spring and the connection
is made. OF course, when the CustOmey
! and the clerk both hear the warning bell,
attention is at once called to the label,
: and an error may thus be corrected before
: it is too lare.
f Some observations made in France by
? NJ. Cosson may throw light upon many
p mysterious fires. In one instance spOn-
! taneOus firing arose from an air current
heated at II f. only. The wood slowly
! CarbOnized at that temperature, and
being thus rendered extremely porous, 8
r rapid absorption Of oxygen resulted, and
| sufficient heat was then produced 10 in
f me the dry material In an other case the
warmth from the air-hOle of q stove was
sufficient to set fire to the woodwork.
The true French polish is one pint OF
spirits of wine added TO a quarter of an
ounce of gum COpsl, the same of gum
arabic and one ounce of sheIIac. This
polish is used for plain wood that has
5 been stained IN imitation Of natural
J wood. The principle of action is the
r floating with oil the gummy or resinOus
substances into the pores, and bringing
the polish up by rubbing. The simplest
varnish is q solution of shellaC dissolved
in naphtha.- Decorator and Furnisher.
The curious "csnals" on the surface of
! Mars are like nothing else known, and
still remain unexplained. They are seen
as nearly straight lines, and appear like
cutting, with parallel sides, extending
. from sea t. sea across the planeJ's CONT
, nents. They are about fifteen miles
wide They were discovered few years
ago by Schiaparelli, an Italian astrOnO-
: mer, and their existence has since been
, confirmed by several other observers.
An artificial ivory of creamy wilderness
and great hardness is now made from
: good potatoes washed in diluted sui
phurlc acid, then boiled IN the same SOLD
ton until they become solid and dense.
They are then washed free of the acid and
slowly dried. This ivory can be dyed ard
{ made useful in many ways ManufsC-
turers' Gazette,
, The Electrical Review gives the follow
| inc ipiu 70 fTDah
bitt:" Melt in 8 cruci0le one and hsf
pounds of copper, and while this is melt
ing get a big lsdle and melt twenty-five
pounds of TIN and three of antimOny;
heat it red hot snd pour the two together
and stir till thoroughly mixed.
When screwiug up the nuts on the ends
of rod it often happens that the rod will
turn with the nut. To prevent this the
nut on the other end must be kept from
turning by screWing on 3 check-nut, snd
g wrench on this will hold the rod while
the first mentioned nut is screwed on.
A scientist, otter 9 careful analysis Of
the impression made upon the retius OF
different degrees e light, concludes that
both white and bIsck sre COlOrs, and both
should haye proper plsCe upon the
chromStiC scale.
German builders use s mixture OF cork,
sand snd lime nodded into bricks for the
construction Of light partition walls. They
say II excludes sound better thsn briCS-
work, IS light and none onductOr Of
heat.
The Electrical Review gives the follow
ing tormula for cement TO- objects which
have to De heated: Iron diuES, loo parts:
clay, 80 parts; common salt, 10 parts
quartz sand, - parts.
/ ParaIlina should never De htStsd shove